The news: On Tuesday, a federal appeals court handed down an opinion that could end net neutrality as we know it. The ruling, courtesy the D.C. district court, could enable Internet service providers (ISPs) like Verizon to engage in traffic shaping, give preference to specific forms of online content, or offer tiered service that requires additional payment in order to use specific services, view particular websites, or browse the web as a whole.

Net neutrality advocates believe that such a ruling puts undue power in the hands of ISPs, which would be in a position to decide which content makes its way to users, and at what price.

The background: The decision is based on the Federal Communications Commission’s (FCC) 2010 Open Internet policy, which the agency adopted, in part, in order to promote the proliferation of broadband services. According to the policy, the FCC views the Internet as, “a level playing field where consumers can make their own choices about what applications and services to use, and where consumers are free to decide what content they want to access, create, or share with others.”

As part of the policy, the FCC attempted to classify broadband ISPs under “common carrier” rules that were originally developed for telephone companies, and which allow for tight regulation. However, House Republicans blocked the bill that would have made the classification official, and Verizon’s lawyers sought a rule change almost immediately thereafter. Tuesday’s opinion finds that because Verizon and other broadband ISPs are not defined as common carriers, they cannot be treated as such. Which, you know, stands to reason.

What comes next: It may sound alarmist, but the appeals court’s decision really could lead to a tiered internet wherein VoIP (read: Skype) and streaming video are billed as premium services (that is, in addition to any charges that you already pay for access to Netflix or Hulu Plus), or where ISPs like Verizon and Time Warner Cableshut off access to specific sites as part of contract disputes, much as they do as cable providers today. Just as Time Warner Cable blocked some of its cable subscribers’ access to CBS for a full month last year, the company could simply choose to block access to sites like Facebook or Tumblr, or charge an additional fee for subscription access to them.

Fortunately, Tom Wheeler, the current head of the FCC, appears to be a proponent of the free and open web as we know it, and has already announced that he’s considering an appeal of the D.C. district court’s decision, and, “all available options … to ensure that these networks on which the Internet depends on to provide a free and open platform for innovation and expression.”

Hopefully, one of those options includes renewing the fight to reclassify the ISPs as common carriers to begin with, making the court’s decision irrelevant, and enshrining the government’s stated dedication to net neutrality in law.